Reply
 
Thread Tools Search this Thread Display Modes
 
Old 11-02-2019, 05:59 PM   #1
Overkill Specialist
 
GMFL's Avatar

 
2014 23' International
Dadeville , Alabama
Join Date: Oct 2015
Posts: 3,260
Images: 4
Blog Entries: 47
OFF-1-2-1+2 switch with Victron BMV

Quick question.
I’m installing 4 LineLine AGM 6 volt batteries in series/parallel, creating (2) 12volt 200ah battery banks. I’m wanting to put in a battery disconnect switch like pictured below. Running the (-) leads from both battery banks through the BMV shunt.
The switch will be in the 1+2 position unless I needed to disconnect the batteries for any reason.
Question.
If the Victron BMV is programmed for the 400ah bank and I set the switch to either bank 1 or 2 and and run the trailer for say an hour pulling amps from just the one bank. If I switch back to 1+2 the bank should equalize back out and not affect the total hrs available correct?

My understanding is that the only thing that would be affected would be the BMV’s calculation of time remaining if it were in position 1 or 2 and not running off all 4 batteries.
Attached Thumbnails
Click image for larger version

Name:	231906F5-C89C-425E-8E11-B59BEE597674.jpeg
Views:	6
Size:	62.9 KB
ID:	355481  
__________________

GMFL is offline   Reply With Quote
Old 11-02-2019, 07:07 PM   #2
Half a Rivet Short
 
2017 30' Classic
Carlisle , Pennsylvania
Join Date: May 2017
Posts: 8,173
Hi

.... ummm .... errr .... that would all be pretty close to perfect with .... ummm.... lithium batteries

If by some chance you happen to be installing AGM's (as you are) they are a bit less ideal in terms of how they charge. The simple answer would be to always run in the 1+2 mode. If you ever run in the 1 only or 2 only, recharge to "full" to reset the system.

Bob
__________________

uncle_bob is online now   Reply With Quote
Old 11-02-2019, 07:17 PM   #3
Overkill Specialist
 
GMFL's Avatar

 
2014 23' International
Dadeville , Alabama
Join Date: Oct 2015
Posts: 3,260
Images: 4
Blog Entries: 47
That would be the plan “to always run in 1+2”. But having the ability to run either 1 or 2 would give me a “Limp” mode “IF” I ever had a cell go bad, and the likelihood would be only one of the 4 batteries would be the problem. I could eliminate the bad bank with the flip of a switch.
GMFL is offline   Reply With Quote
Old 11-02-2019, 07:37 PM   #4
Half a Rivet Short
 
2017 30' Classic
Carlisle , Pennsylvania
Join Date: May 2017
Posts: 8,173
Hi

There is another way to go. You *could* put in a second 712 and a second shunt. That way you would know what was what no matter how the switch was set. I can think of at least one other AS with a pair of 712's and the ability to run off either half of the battery set .... some guy named Bob

One basic thing it allows you to do is to monitor the voltage on the "other half" of the setup. The currents can get a bit scary if one battery is fully charged and the other one is pretty far down ....

Bob
uncle_bob is online now   Reply With Quote
Old 11-03-2019, 08:53 PM   #5
Rivet Master
 
waninae39's Avatar

 
2017 22' Sport
NCR , Ontario
Join Date: Feb 2017
Posts: 1,632
i see no reason not to run 1+2 all the time.

this is not an airplane with two independent systems.

PLUS, the victron system will keep the two series pair in sync and balanced
waninae39 is offline   Reply With Quote
Old 11-03-2019, 08:57 PM   #6
Rivet Master
 
2017 27' Flying Cloud
Fort Worth , Texas
Join Date: Sep 2017
Posts: 653
I have that switch. I can isolate the trailer, the inverter, or both (off). Remember, the inverter has a parasitic load. If I’m concerned about battery power while boondocking, I run in trailer (no inverter) only mode.
billrector is offline   Reply With Quote
Old 11-03-2019, 08:59 PM   #7
Overkill Specialist
 
GMFL's Avatar

 
2014 23' International
Dadeville , Alabama
Join Date: Oct 2015
Posts: 3,260
Images: 4
Blog Entries: 47
Quote:
Originally Posted by waninae39 View Post
i see no reason not to run 1+2 all the time.

this is not an airplane with two independent systems.

PLUS, the victron system will keep the two series pair in sync and balanced
I agree. I would run the trailer off both banks all the time unless there was a problem. The purpose of the battery selector switch would be to have the option of removing a pair of batteries from the system “if” there was ever a problem with one of the cells by simply turning the switch. This would allow you to still operate the trailer with the other 12 volt bank.
GMFL is offline   Reply With Quote
Old 11-03-2019, 10:56 PM   #8
Rivet Master
 
waninae39's Avatar

 
2017 22' Sport
NCR , Ontario
Join Date: Feb 2017
Posts: 1,632
i have three separate disconnect switches
1. to remove all battery connections
2. remove all solar connections
3. remove all power to anything up front 7way, jack and 3rd party mover connection

the #3 is used when camped so no one can raise or lower the electric jack
#1 and #2 are used when i work on the electrical stuff inside
__________________

waninae39 is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Victron BMV-712 panel lights turn off? marter Batteries, Univolts, Converters & Inverters 7 08-19-2018 12:37 AM
Victron BMV-712 install in 2017 30 International dmcgaugh Batteries, Univolts, Converters & Inverters 3 03-09-2018 01:24 AM
Incorrect readings Victron BMV-702 NoResults Batteries, Univolts, Converters & Inverters 1 06-01-2017 04:51 PM
Victron BMV 702 install using solar prewire Brav Batteries, Univolts, Converters & Inverters 4 11-21-2016 02:22 AM
Victron Energy BMV-702 Battery Monitor TinVenture Electrical - Systems, Generators, Batteries & Solar 5 10-15-2016 09:49 AM


Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by the Airstream, Inc. or any of its affiliates. Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 05:39 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
×